The Mix Up
by UseAnotherName
Summary: "Uh, Tony," Steve finally spoke up, once it was apparently clear he and his AI were done with their bickering contest. "What's going on?" He eyed both Tonys. "Who's that?" Steve/Tony. Parallel Universe. Crackish.


**A/N: Still unbeta'd.**

Parallel Universes, as it turns out, are indeed real. Tony found this out the hard way one day when he walked into the kitchen and found his exact replica standing there.

"Okay, ha-ha, very funny, Loki. _Get out_." He really wasn't in the mood for magic today. Maybe tomorrow.

"Loki? You all are friends with him here in this universe? Strange." His doppelganger said.

 _This_ universe?

Perhaps it wasn't Magic Monday after all.

Well _shit_.

"What do you mean 'this' universe?" Tony questioned, eyeing the other man carefully.

"You and I need to have a little talk," the other Tony said.

...

So as it turns out parallel universe-okay, PU for short, no jokes-Tony had been bored with designing and building _regular_ everyday items and decided to move on to bigger and better ideas. And no, our Tony was not at all bothered by the fact that PU Tony had seemed to surpass him in the creation department. Not. At. _All_.

Anyway, the other Tony had started to tinker with the idea of building a teleportation devise of sorts.

Clearly he succeeded.

Still, Tony was not jealous. Nope.

But, what was supposed to be a simple idea, something to transport him from room to room- and not at all into Fury's office to set up booby traps-turned out to send him to another _goddamn universe_.

How he ended up here out of all places, well that was anyone's guess.

Tony rubbed his temples, contemplating just saying fuck it and walking away. He really wasn't in the mood for this today. "Has anyone else seen you?"

"Uh, no. Kinda just got here."

Tony wasn't quite appreciating the other man's tone. Where did he get off being so rude? He sighed. "Right. It's probably for the best. Let's get you out of here. Don't need anyone else to see you." It's not Freak Out Friday yet.

...

Down in his lab- the one place Tony knew the other Avengers would stay out of (well except for Clint that one time with the...well it wasn't important what he had walked in on Tony doing, all that's important was that the man will never _ever_ come down to the lab again)- he had Jarvis run various tests on this _other Tony_ to be sure he was indeed who he said.

"Okay, here's what we're going to do," Tony said after way more that strictly necessary tests had been ran. "You are going to stay down here. You are not going to touch anything. You are not going to talk to anyone, and more importantly you are not going near that." He slapped the other man's hand away from the Iron Man suit.

"You know I could make some improvements on this for you." PU Tony gave Tony a smug look.

Tony had never wanted to punch himself in the face more.

"I need to make some calls. Just don't touch _anything_." Who does one even call for a situation like this? Steven Strange? Reed Richards? Probably Richards. As long as he doesn't bring that asshole Johnny with him. Tony really hated that guy.

...

"Sir?" Came Jarvis's unusually calm voice for what was probably not a calm situation an hour later. "It appears your better half has not followed your instructions."

"What," Tony said as he gritted his teeth, not looking up from his tablet- all the information on parallel universes was _bullshit_ , "has he done?"

"He has left the lab."

Damn it.

"Where is he?" Tony's grip on the tablet was getting tighter.

"The hallway. He's found Captain Rogers."

Of course he did. "That son-of-a-bitch. What are they doing?"

Jarvis hesitated. "It's probably best if I just show you, Sir."

That didn't sound good. Tony braced himself. Jarvis transferred the data to his tablet and...huh. That was interesting. He wasn't even aware Captain America knew _how_ to kiss like that.

He watched for a full twenty seconds more as his impersonator tongue fucked Steve's mouth- -or was it the other way around, he wasn't quite sure- before he told Jarvis to shut it down.

And he was going to absolutely forget the way Steve had a near death grip on Not Tony's upper arms.

"That bastard," he grumbled. Because of course. Of course PU Tony would get to Steve first. This was just how things in life worked out for Tony Stark. He was gonna make his move on Steve! Eventually. In a few ye..months. Weeks.

Well damn it _all to hell_.

"Sir?" Jarvis spoke up, nearly making Tony jump. Sometimes a man can forget when lost in deep thought. "If I may point out: Captain Rogers is still unaware of the parallel universe Tony..."

Oh right. There still may be hope after all.

...

"Okay, remember what I said about not leaving, or talking to anyone?" Tony snapped the second PU Tony had returned. And if the other man had looked a little more smug than usual Tony chose to ignore it. _Bastard_.

"Technically we weren't talking-"

"Just shut up." Tony rubbed his temples. A sigh. "You really just couldn't help yourself could you? Just had to come into my universe and fuck things up? What; you don't have enough of Steve in yours? Had to steal mine too?"

PU Tony snorted. "Yeah, right. Like that would ever happen. Steve Rogers hates my guts in my universe."

Not much different here, so...

"Seriously?" Tony studied the other man. "So you just...wanted to see what would happen?"

The other man shrugged. "Pretty much. He's a good kisser, great ass. Funny thing, I'm actually with Bruce in my universe," he mentioned, as if that had anything to do with why he had attacked Steve with his mouth.

And why Steve had reciprocated so eagerly.

"You and Banner, really?" Tony was slightly intrigued. But not at all really surprised.

"Yeah, we've got this whole "on again off again" thing going on," PU Tony said with the wave of a hand.

Tony, whose mind never stopped working overtime, thought about this for a moment. "So..you and Banner... how do you...you know?"

PU Tony deadpanned. "It's complicated."

Yeah. Like things with he and Steve wouldn't be. "Right." Tony shook his head. "So uh, with that being said, how do you think your Bruce would feel if he found out about you and my- er, _this_ Steve?"

Apparently the man had an answer for that. "Remember, way back, when I said we had an on again off again thing?" Tony nodded. "We're off."

Convenient. Tony sighed. "Of course." He really needed to find a way to get this Tony back to his own universe before things got worse. _How could things get worse? The man already tongue fucked Captain America in the hallway_ , Tony's mind helpfully supplied. Not that it appeared Steve had minded. In fact, if the video were any indication it had appeared that Steve had enjoyed himself quite a lot.

Fucking parallel universe Tony Stark.

Also, touché.

"Okay, new plan," Tony had started and then looked over at one Steve Rogers standing in the doorway and, _great_. "Uh, Jarvis? Security breach."

His AI had finally decided to pipe up. "Sir, Captain Rogers is here."

"Yeah, I noticed. And I'm firing you and giving Dum-E a promotion." Tony snapped. Dum-E whirred around, did a happy beep and knocked a shit ton of tools off a table. Maybe not.

"I'm afraid you're not authorized to do that, Sir."

That's the last time he creates an AI with so much _smug_.

"Uh, Tony," Steve finally spoke up, once it was apparently clear he and his AI were done with their bickering contest. "What's going on?" He eyed both Tonys. "Who's that?"

Tony looked back at his replica (who had the audacity to _wink_ at Steve. _Bastard_.), then to Steve. "Funny thing..."

...

"Parallel Universe? Really?" Steve looked back and forth between both men. "And I thought I'd seen it all," he mumbled.

"Don't worry he's not staying," Tony said, giving his imposter a look.

"That's debatable," PU Tony said. He crossed his arms and looked away, then looked to Steve and smiled.

That was it! He had to go, _now_.

"You," Tony said pointing to his rival, "don't move." He grabbed Steve by his amazingly ridiculous upper arm. "Captain Rogers and I need to have a talk." A pause. "In _private_."

"Been there, done that. _First_." PU Tony shot back.

If Tony were to murder him would it be homicide or suicide? Eh, technicalities.

...

So many things Tony wanted to say to Steve but the second they rounded the corner it was Steve who spoke first.

"I'm sorry, Tony. I really feel like an idiot here."

Wait, what?

Tony gave the other man a look. "Uh, for what?" He should probably let go of Steve's arm now... eh, fuck it; Steve didn't seem to mind and what's done was done. He wasn't letting go. "You, to my knowledge, have nothing to be sorry for. I'm the one who has been keeping the fact that a parallel universe version of me has been here this whole time." He made a face. "I probably should have told someone-besides Jarvis, he doesn't count-but I didn't, so..."

Steve just shook his head and looked down. "No, Tony, I feel stupid because..."

Because _what_? Tony was not a man who patience was a friend of. He tightened his grip on Steve's arm. "Because?"

A sigh. "Because I finally worked up the nerve to put a move on you and it wasn't even the right you."

Oh.

Ohhh.

Wait, _what_?!

Tony gripped his arm even more. "You... _you_ kissed me- him? _What_?"

As if the concept of a parallel universe wasn't strange enough. Now there's this. _Great_.

"I'm sorry, Tony. I didn't know." Steve honest to God said, from like, the bottom of his heart. And Christ, that was so Captain America-like of him wasn't it? Apologizing for something he didn't even do wrong. Tony needed a moment.

"I..."

Maybe two.

" _What_?" Was still all Tony could come up with.

Steve brought his eyes back up to Tony's. "I really thought he was you, in my defense."

Oh, this was still going on? Tony shook his head. Slightly-only slightly-released his grip on Steve's arm and said: "Would you just shut up already with the apology and kiss me?" A pause. "The _real_ me?"

"Um.."

Christ. "Jarvis, would you please?" Tony asked the ceiling in particular.

"Captain Rogers, the man in front of you is indeed our Tony Stark: arrogant,narcissistic, billionaire-"

"Thank you, Jarvis that will do," Tony snapped. No seriously, Dum-E's the new Jarvis _Demoted_.

Steve still seemed a bit hesitant so-

"Fuck it." Tony pulled the taller man closer closing the distance between them.

Take _that_ parallel universe Tony.

...

"Hey, where'd he go?" Tony looked around his blissfully empty-save for Steve and himself-lab. "Jarvis? Do I have a soon-to-be media crisis on my hand?" He looked out the window. God help them all if two Tony Starks were released on this world.

"I'm reluctantly happy to report that parallel universe Tony just seemed to...disappear," Jarvis said.

"Reluctantly happy?" Tony questioned. So this was what betrayal felt like.

"He was very nice to me, Sir."

"He was nice," Steve added.

Of course. Traitors. _Whatever_. "So he's just gone?" Tony mused this for a moment. "Guess his Bruce figured out how to bring him back." Thank _god_. Save Tony the headache. And time.

"His Bruce?" Steve questioned.

"Yeah, it's this whole big thing...you know what, never mind, let's just..." Tony pulled Steve closer.

"Kiss some more?" Steve asked. And goddamn it all to hell if he didn't blush.

"Yeah, that. Because I've had a _hell_ of a day."

Fuck parallel universes.


End file.
